There are two versions of the standard playing card: the bridge size and the poker size. The bridge size is narrower than the poker size. A poker size card is 2.5 inches wide by 3.5 inches tall. A bridge size card is 2.25 inches wide by 3.5 inches tall.
The difference in size between the two versions is about 10 percent of the total card. The names refer only to the size of the card and do not mean that the card type is only used for playing poker or bridge. Over 95 percent of poker rooms in United States casinos use bridge-sized cards, while 95 percent of blackjack games use the poker-sizes cards.